In laparoscopic surgery, access is gained to an interior surgical site by making one or more short incisions in the body which extend down to the interior surgical site, and then inserting a hollow tube or cannula into each incision so that the cannulas can act as liners to hold the incisions open and thereby provide portals leading down to the interior surgical site. A laparoscopic procedure can then be performed by passing instruments (e.g. cutting devices, clamps, viewing apparatus, etc.) down the cannulas so that the distal working ends of the instruments can be positioned and used about the surgical site, while the proximal handle ends of the instruments remain outside the body where they can be grasped by the surgeon.
Laparoscopic procedures frequently involve the repair and/or removal of tissue from the interior surgical site, and often require that some sort of closure be made to the tissue which is being operated upon. Such closure can be effected through the use of conventional needles and suture, surgical clips or staples, or other known closure means. In this respect, it has been found that the use of conventional needles and suture can have significant advantages in many laparoscopic procedures, since they generally allow the tension of the closure to be dynamically adjusted during suture deployment. At the same time, however, the use of conventional needles and suture can also present significant difficulties in laparoscopic surgery, on account of the limited access provided to, and at, the interior surgical site.
One aspect of using conventional needles and suture which can be particularly difficult to accomplish in a laparoscopic setting is that of tying knots. In particular, it has been found that it can be very difficult to properly manipulate the suture ends within the body so as to tie the knots, given the limited space available adjacent the interior surgical site. In addition, it will also be appreciated that the remote nature of the surgical site, and the limited cannula access provided to that site, further complicates this procedure.
Currently, surgeons generally use long straight forceps to reach into the interior surgical site to manipulate the suture ends during knot tying. This tends to be a time-consuming and inconvenient method to tie knots in a laparoscopic setting. In addition, such long forceps tend to offer limited suture control at the surgical site, since there is essentially no tactile feedback to the user when grasping the suture and no reliable way to vary the degree of engagement between the forceps and the suture. Furthermore, with such forceps the outer diameter of the forceps changes according to the positioning of the forceps' jaw members; when the two jaws are opened wide, the forceps will have a relatively large outer diameter, and when the jaws are closed down, the forceps will have a relatively small outer diameter. This characteristic can present problems in certain surgical sites which may be too cramped to permit the forceps' jaws to open fully. In addition, the fact that the outer diameter of the forceps changes according to the positioning of the forceps' jaws means that the surgeon must take care to ensure that nothing is placed adjacent the jaws which might interfere with operation of the forceps' jaws. Thus, for example, suture cannot be coiled tightly about the exterior of the forceps' jaws when the jaws are closed and must thereafter be opened, since the wound suture might inhibit opening of the jaws.